fiuba/alfred

class CannotUpdateNameError < StandardError
    def initialize
        super("File's name cannot be updated after being set.")
    end
end

class AssignmentFile
    include DataMapper::Resource

    storage_names[:default] = 'assignment_files'

  before :save, :complete_path

    belongs_to :assignment

  property :id, Serial
    property :inner_path, String, :accessor => :protected, :field => 'path'

    validates_presence_of :inner_path
    validates_uniqueness_of :inner_path
    validates_format_of :inner_path, :with => /.+(?!\/temp\/).+/i

    def name
        return nil if self.inner_path.nil?
        Pathname.new(self.inner_path).basename.to_s
    end

    def name=(new_name)
        return if new_name.nil? || new_name.empty?

        new_name = new_name.downcase
        raise CannotUpdateNameError if self.inner_path && self.name != new_name

        self.inner_path = calculate_path(new_name)
    end

    def path
        self.inner_path
    end

    def complete_path
        if self.path =~ /^\/assignments\/temp\/.*/ && !self.assignment.nil?
            self.inner_path = calculate_path(self.name)
        end
    end

    def calculate_path(file_name)
        path = ''
        if !self.assignment || self.assignment.id.blank?
            path = "/assignments/temp/#{file_name}"
        else
            path = "/assignments/#{assignment.id}/#{file_name}"
        end

        return path
    end
end